Speedometer for aeroplanes and other aerial devices.



0. A. DANIELSON. 4 SPEBDOMETBR PoR ABROPLANES AND OTHER AERIAL DEVI-GBS.

APPLICATION FILED JAN.11, 1913.

Patented Jan. 5, 1915.

A MATE nur onirica. y

oscar. a. DANIELSON, oF ivEwYonK, N. Y..

SPEEDOMETER FOB. AEROPLANES AND OTHER AERIAL DEVICES.

Specification of Letters Patent.

Patented Jan. 5,1915.

`Application filed January 11, 1313. Serial N o. 7451,3 8.

To all whom it may concern.'

Be it known that ,1, OSCAR A. DaifInLsoN, a citizen of the United States, residmg at New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Speedometers for vAeroplanes and other Aerial Devices, of whi'chthe following is a specification, reference being had therein to the accompanying drawing.

f My present invention relates to a speedspeedometer does, for an automobile, and

.other similar fast-moving vehicles,

AIn view of the factzthat aeroplanes and other aerial machines are propelled through the air Without contact with the earth .the methods and devices now commonly employed for measuring the speed o'f automo-H biles are not available.I It becomes necessary to resort to o tical means; and to make observations of o jects on the earthibelow in order to determine the speed at which these objects are being passed over by theaerial device traveling above. .An aeroplane or airship of given dimensions and ldesign with the propellers running at a given speed would .travel throughvthe air at a. relative. speed. which speed, having once been ascertained, could thereafter be instantly determined by a revolution counter on the propeller'shaft.` But it is only in calm air that the speed of an aeroplane through the air is the same as its speed with relation to the earth, and calm air is seldom experienced.

Since the air is always more or less disturbed by Winds, it will add its velocity t0 or subtract it from that of the speed of the aeroplane with relation tothe earth accordingly as the aeroplane may be going in thel same or the opposite direction. For eX- ample, if an aeroplane is traveling at the rate of fifty miles per hourthrough the air against a wind of twenty-five miles per hour, its speed with relation tothe earth 'would be 50 minus 25, or twenty-five miles per hour; or 1f the aeroplane is traveling with a `wind having a velocity of twenty-five miles per hour the resultant speed would be 50 plus 25 or seventy-five miles per hour.

, Further, ifthe aeroplanefis` not traveling directly with or directly against the Wind, but at a certain angle to thedirection of .theywind, the resultant speed land direction with relation to the earth wouldl be determined` by the law of the parallelogram of forces. i

The invention consists essentially in meansvforqobserving objects onI the earth,

means for'causing one of the elements of the observing means to travel 'inthe oppo site directlon' to that of' the aeroplane,

- thereby causing said element -to standstill over the objects beingobserved and to cause the objectsto remainstationary within the field ofv vision for anj appreciable period of time, long enough tof ascertain that they aref standing still; means for determining itheV element, which speed,

speed of the traveling Y y when the images of he objects are station- 'ary will be thegspe'ed of Athe4 aeroplane, and

meanspfor focusing the `observed objects to convenient dimensions.

And the linventionalsoY comprises numerv ous details'and peculiarities in the constructlon, arrangement and combinatlon of parts,

aeroplanes andthe like?, Fig. 2 is a cross section on the line 2,2 of Fig. 1. Fig. 3 is a cross section onthe line 3,'"3 'of Fig. 1. Figll'l is a `vertical section through the reflecting devices in Fig. l that are used for the purpose` of observing objects on the earth.l i

Similar characters of reference designate lcorresponding parts throughout the, differ-y ent ligures of the drawing. The essential mechanicalv parts of my improved speedometer construction may be carried in any suitable framework, the silnf pler the better, and asian illustration kof the saine I v`have 'shown in the drawing the specimen. frame consisting of I a vpalr of parallel4 tubesfl, 1, 'preferably of -steel vor other metal,I and similar to bicycle tubes,

the same being connected together at their ends and. intermediate points by plates 2, 3 and 4. This frame may be mounted inthe aeroplane in any desired manner. One way of mounting involves the use of a wire 5 secured to the upper tube or rod 1 near the ends thereof, and provided with a helical spring 6 engaging the same near the center and used to suspend the apparatus from the aeroplane in such a way that it can beswung to an anglewith the longitudinal axis of the aeroplane, when, owing to the direction ,of the wind, the line oflight with relation to the earth does not coincide with the direction of flight through the air.V The spring 6 also serves `as a shock-observer to prevent vibrations from the aeroplane being transmitted to the apparatus. 'lhe grip or 'handle7 at one end 'of the frame enables.

the operator to swing the apparatus to the desired angle with one hand, while the other hand is employed in manipulating the crank handle which drives the chain and other part's. 8 designates a carrier which supports one of the telescopic' parts employed as means for sighting objects on the earth. This carrier 8 is formed at top and bottom with curved flanges 9, which closely embrace the tubes or rods 1, 1, but slide easily thereon.

The telescope 10 consists of the tubes 11 and 12, the tube 11 being securely fastened by 'a bolt 13 or by any other suitable means' to the carrier 8, see Fig. 3. l

The tube 12 has at its lower end suitable lenses as 14, while the tube 11 has at its upper end a lens 15, prism 16 and lens 17, or some suitable reflecting mirror device so that the objects underneath the telescope 10 are reiected through the prism or mirror so asto be thrown flpm a` vertical yto a horizontal line. The mirror or prismI is arranged within a casing 18 `supported on the upper end of the telescope l0 and hence movable with the carrier 8 as it travels back and forth on the tubes 1 of the main frame.

On vthe main frame `near one end thereof is an eye-piece 19 having a lense 20 and a reflecting prism 'or mirror 21. Said eyepiece 19 is further provided with a tube 22 secured thereto at right angles andlying lin the same horizontall plane as the casing 18 within which is the prism 16. The refleeting prismI 16 travels back and forthl relatively to the. eye-piece and its prism, but at all times the two'prisms are in line with each other so that an object reiected by one telescope 1,0.

will be reflected alsoby the other, and thus it .will be V'seen that an observer looking downward through the eye-piece 19 will see the objects whichv are directly beneathfthe The mechanism for reciprocating the telescope 10 consists essentially of sprocket wheels 23 and 2.4 around which passes a ing down through the belt orchain 25. Sprocket wheel 23 is supported on a shaft 26 that is journaled in the vertical end part 2 of the lmain frame. Sprocket wheel 24 is suitably journaled for rotation in the` vertical part 34 of the main frame. A connecting rod `27 lis pivotally connected to' the chain 25 by a screwV or pin 28 and at its bther end said rod 27 is suitably pivoted to the telescope carrier `8 by means of a convenient pin, as for instance the wrist pin 13.. Also pivoted to theconnecting, rod 27 at 'a point near the telescope 10 is al link 29 which is pivoted to a shutter 30 working. through a slotv31 in the casing 18 and designed-to cover or 'uncover the lens 17 andvreecting prism or mirror 16. It will be obvious thatas the connecting rod 27is raised and lowered during the movements of the `carrier the shutter 30 will open and close, so that while the carrier is moving in one direction; the shutter will be open, and while movingin-the opposite direction it will be closed.

The chain 25 which passes around the sprocket wheels 23 and 24 is actuated' by the sprocket wheel 23 which has the'driving function and is supported on shaft 26 as already stated., p

Referring to Fig. 2, it will be seen that y loose on shaft 26 is a gear wheeli32 having Atern .commonly used on automobiles. The

observer by reading the speedometer dial 40, therefore, 4can easily ascertain the speed of.- revolution of the sprocket wheels' and the chain 25. 'Y

Assuming the apparatus to be attached -to anl aeroplane which is traveling above the earth in the direction shown by the uppery arrow, will be reiected through the telescope byl the reflecting prism 16 to the other prism 21 and thus through the eye-piece 19 'where they are seen by the operator who is looklens 20. If the chain belt 25 is not running the telescope will be stationar with respect to 'the-- aeroplane, and will be moving rapidly over the ground so that the objects reflectedl from the ground through the telescope and mirrors to the eye-piece will appear to be. sweeping rapidly.l across 'the field of vision. If, however, the crank is' *operated so as to cause the belt or chain 425 to travell in the direction indicated objects on the ground beneath by the lower arrow, the objects reflected from the ground throughthe telescope and prisms will appear intermittently, that is to say, only while the shutter 30 is open, and thus while the reflecting prism 16 1s on the proper side of its circuit of travel and moving in a direction opposite to the travel of the aeroplane. As the speed of the belt 25 approaches the speed of the aeroplane the objects on the earth will pass less and less swiftly across the field of vision until finally they become stationary, which will indicate that; the speed of the belt or chain 25 equals the speed of the aeroplane. This speed can be instantly read on the dial of the speedometer 40.

lt would seem tha'tl a simpler way of con-` structing my invention would be to attach the movable -reecting prism directly to the chain or belt andv allow it to pass over the sprockets on its travel to and fro, thus avoiding the use of the carrier and connectingV rod, but in the pratcical working of this invention it is necessary to make observations over a wide range of altitudesfrom a few eet'to several thousand feetand it becomes necessary to provide an adjustable telescope to regulate the size ot the image of terrestrial objects to such dimensions as will make accurate observations possible. To carry such a bulky piece ot optical apparatus around sprockets or pulleys on a belt or chain is diiiicult, and, therefore, ll have found it desirable to employ an apparatus of the simple and convenient form, which ll have illustrated in the drawmg.

lin the operation of the device the telescope l0 will 'rst be adjusted.v for the altitude for which it is being lused, so as to give an image of suitable dimensions in the eye-piece 19. The operator, taking 'hold of the end of the loosely-supported trame by v means of the handle 7, or otherwise, swings the apparatus into line with the direction of aerial ight with relation to the earth, and looking into the eye-piece turns the crank, gradually increasing the speed until the images of the objects on the Yearth cease to move across the field of vision and appear stationary. @t course, as already explained, it will be clearly understood that it is only during one-half of each revolution of the chain, that is to say While the carrier 8 is moving in the direction shown by the lower arrow, which is opposite to that of the direction of the movementof the aeroplane, that the 'shutter 30 will be open so as to permit the rays of light to pass from the object to the eye-piece. 0n the reverse stroke when the carrier 8 is moving in the same direction as the aeroplane the shutter 30 will be closed, shutting od all light -from the reflecting prisms. Then the image seen in the eye-piece becomes stationary it indicates, o course, that the carrier andy the telescope are moving at the same rate of speed as the aeroplane, but in the reverse direction so that the telescope remains directly over the objects seen in the eye-piece during each stroke in the direction or' the arrow, therefore the speed of the chain is the same as the speed oit' the aeroplane, and is promptly read on the speedometer dial.

Having thus described my invention,what l claim as new and desire to secure by Letters Patent, is

1.ln a speedometer for aeroplanes or 4other aerial devices, the combination with a moving aerial body,'of a device relatively movable in a direction longitudinal of the aeroplane thereon for reiiecting objects on the earth.

2. in a speedometer for aeroplanes or other-aerial devices, the combination with a movingFaeriaI body, of a device relatively movable kin the direction of the line of flight thereon for reflecting objects on the earth, and means for registering the speed of the latter device.

3. in a speedometer for aeroplanes or other aerial devices, the combination with a moving aerial body, of a device thereon for refleeting objects on the earth, said device being relatively movable in the direction of Hight and means for imparting a variable speed to said device.

at. ln a speedometer for aeroplanes or other aerial machines, the combination with an aerial moving vehicle or element. of means thereon for observing objects on the earth, means for imparting a relative movement to the latter means in the direction of flight, and means for measuring said movement when the reected images of earthly objects are stationary. j

7. ln a speedometer for aeroplanes or other aerial devices. the combination with a moving aerial body`r of means thereon for reflecting terrestrial objects, means for imparting movement to the latter means in a direction opposite to that in which the aerial body is moving, and means for indicating the speed of the observing means at a time when the reflected image of the terrestrial object is stationary.

llo

8. In a speedometer for aeroplanes or other aerial devices,l` the combination with a moving aerial-body, of a relatively movable ,devicethereon for reflecting objects on the earth, :l carrier for yimparting motion to the reflecting means in a direction op# posite to that in which vthe aerial body is moving, and means for indicating the speed of said carrier at a time when the reflected image is stationary.

'9. In a speedometer for aeroplanes and the like, the combination with an aerial moving'body, of relatively movable reflectin means whereby images of terrestrial obJec'ts can be seen, a carrier for the movable reflecting means, said carrierv operating in a direction thevreverse of that in which the aerial body is traveling, and,means for registering the speed of the carrier.

10. In a speedometer for aeroplanes and the like, the combination with a movable aerial body, of reflecting means relatively movable in a direction longitudinal ofl the v aeroplane, other reflecting means on' the aerial body and stationary relatively therea to, means for supporting they movable refleeting means, means for' imparting motion to said support, and means for registering the speed of said reflecting means.

11. In a speedometer for aeroplanes andl the like, the combination of a moving aerial body, reflecting means, relatively stationary reflecting means relatively movable inv a direction longitudinal of the aeroplane, a carrier for the movable reflecting means, guides .for supporting and directin the motion of' imparting reciprothe carrier, means for eating motion to the 'carrier at variable speeds, means for registering the speed for the purpose of determining the speed of the aeroplane.

12. In a speedometer forxaeroplane's and4 the combination of a frame, a tele- 1 the like,

scope, a carrier for lsaid telescope, a reflecting prism for changing the angle at which an object is viewed through the telescope, wheels journaled in the frame, a belt or chain passing around said wheels and attached to the carr1er,'means for actuating the belt and wheels in order to reciprocate the carrier in a direction longitudinal of the aeroplane, and an eye-pieceon the frame having a reflecting prism for viewing the images received through the telescope.

13. In a speedometer for aeroplane's and 'the like, the combination of a -main frame,

means for supporting it'from an aeroplane or similar body, a telescopic device for viewing objects on the earth, reflecting means arranged in connection with the telescopic device for changing the. angle at which the images are viewed, a carrier for the teleplane,

ving over the same,

scopic and reflecting means, and means for imparting a rec1procatory motion to said carrier 1n a ,direction longitudinalof the aeroplane, together with an eye-piece'on the y frame having reflecting means receiving the ,images transmitted by the other-reflecting means from the telescope.

14. In a speedometer for aeroplanes or the like, the combination of a frame, reflecting means thereon whereby images of objects on the earthv can be seen, a carrier for the reflecting means, means for reciprocating said carrier in a direction longitudinal of the aeroplane, an eye-piece on the frame through which images received by the aforesaid reflecting means can be viewed,

` and a register for indicating the speed of the carrier.

15. In a speedometer for aeroplanes and the like, the combination with a moving aerial body, of a device thereon relatively movable in the direction of flight for reflecting objects on the earth, acarrier for said device having anintercepting shutter sliding vertically over the reflecting means4 for the purpose of cutting of the light from the .reflecting means while the latter is traveling in the same direction as the aerobut said shutter sliding away from the reflecting means to afford free access to the light when the carrier is moving in a d1- the carrier, and means means or intercepting the light at times and at other times affording free access to the light, a rod attached to said shutter, a

second rod pivote'd to -the carrier and to the shutter rod and also pivotally connected withthe belt'or chain, so that as .the latter revolves thev shutter willreciprocate andthe reflecting means allowed to receive the light when the carrier is movlng in one direction and becut oil' from the light when the carrier is moving in the opposite direction.

In testimony whereof I aflix my signature in the presence of two witnesses. y OSCAR A. DANIELSON. p Witnesses L. S. BERRINE, LAURA- E. SMITH. 

